Most MH manufacturers use a third party AC system. The only thing supplied by the chassis manufacturer is the compressor. One of the popular suppliers is Evans Tempcon. Contact Winnebago to find who they used. You can download wiring schematics for their system from the Web site.
Evans Tempcon, Inc - Technical Support
Chuck & Teri, 1999 35 ft. Dolphin 5350, F53 Chassis with tag axle, Chassis build date 1/99 in Mexico, Banks System, Trans Command, Air Lift Air Bags on rear, Koni Shocks, Blue OX TruCenter, TigerTrak track bars front and rear, Roadmaster 1-3/4" rear auxiliary sway bar, 2013 VW Passat TDI SEL Premium, 1994 36 ft. Avion 5th Wheel. FMCA #F430129